diff --git a/src/server_manager/install_scripts/install_server.sh b/src/server_manager/install_scripts/install_server.sh
index f9fcca49..1302f17f 100755
--- a/src/server_manager/install_scripts/install_server.sh
+++ b/src/server_manager/install_scripts/install_server.sh
@@ -19,6 +19,9 @@
 
 # You may set the following environment variables, overriding their defaults:
 # SB_IMAGE: The Outline Server Docker image to install, e.g. quay.io/outline/shadowbox:nightly
+# CONTAINER_NAME: Docker instance name for shadowbox (default shadowbox).
+#     For multiple instances also change SHADOWBOX_DIR to an other location
+#     e.g. CONTAINER_NAME=shadowbox-inst1 SHADOWBOX_DIR=/opt/outline/inst1
 # SHADOWBOX_DIR: Directory for persistent Outline Server state.
 # ACCESS_CONFIG: The location of the access config text file.
 # SB_DEFAULT_SERVER_NAME: Default name for this server, e.g. "Outline server New York".
@@ -167,7 +170,7 @@ function docker_container_exists() {
 }
 
 function remove_shadowbox_container() {
-  remove_docker_container shadowbox
+  remove_docker_container "${CONTAINER_NAME}"
 }
 
 function remove_watchtower_container() {
@@ -293,7 +296,7 @@ function start_shadowbox() {
   # TODO(fortuna): Write API_PORT to config file,
   # rather than pass in the environment.
   local -ar docker_shadowbox_flags=(
-    --name shadowbox --restart always --net host
+    --name "${CONTAINER_NAME}" --restart always --net host
     --label 'com.centurylinklabs.watchtower.enable=true'
     -v "${STATE_DIR}:${STATE_DIR}"
     -e "SB_STATE_DIR=${STATE_DIR}"
@@ -309,8 +312,8 @@ function start_shadowbox() {
   STDERR_OUTPUT="$(docker run -d "${docker_shadowbox_flags[@]}" "${SB_IMAGE}" 2>&1 >/dev/null)" && return
   readonly STDERR_OUTPUT
   log_error "FAILED"
-  if docker_container_exists shadowbox; then
-    handle_docker_container_conflict shadowbox true
+  if docker_container_exists "${CONTAINER_NAME}"; then
+    handle_docker_container_conflict "${CONTAINER_NAME}" true
     return
   else
     log_error "${STDERR_OUTPUT}"
@@ -362,7 +365,7 @@ function check_firewall() {
   # TODO(JonathanDCohen) This is incorrect if access keys are using more than one port.
   local -i ACCESS_KEY_PORT
   ACCESS_KEY_PORT=$(fetch --insecure "${LOCAL_API_URL}/access-keys" |
-      docker exec -i shadowbox node -e '
+      docker exec -i "${CONTAINER_NAME}" node -e '
           const fs = require("fs");
           const accessKeys = JSON.parse(fs.readFileSync(0, {encoding: "utf-8"}));
           console.log(accessKeys["accessKeys"][0]["port"]);
@@ -407,6 +410,8 @@ install_shadowbox() {
   # Make sure we don't leak readable files to other users.
   umask 0007
 
+  export CONTAINER_NAME="${CONTAINER_NAME:-shadowbox}"
+
   run_step "Verifying that Docker is installed" verify_docker_installed
   run_step "Verifying that Docker daemon is running" verify_docker_running